Mitsubishi Electric PAC-TZ02-E Service Manual page 14

Notes on replacing the parts
When reinstalling the parts that are listed below, observe the tightening torques in accordance with Table 8-1.
Always use a new O-ring or gasket.
Table 8-1
Size
[inch]
Gasket G1
Attached packing Air vent (manual)
Draining the cylinder unit
WARNING: DRAINED WATER MAY BE VERY HOT
1. Before attempting to drain the cylinder unit isolate from the electrical supply to prevent the immersion and booster heaters burning out.
2. Isolate cold water feed to DHW tank.
3. Attach a hose to the DHW tank drain cock. The hose should be able to withstand heat as the draining water could be very hot. The hose should drain to a place
lower than the DHW tank bottom to encourage siphoning.
Open a hot water tap to start draining without a vacuum.
4. When the DHW tank is drained close drain cock and hot tap.
5. Attach hose to water circuit drain cock. The hose should be able to withstand heat as the draining water could be very hot. The hose should drain to a place lower
than the booster heater drain cock to encourage siphoning. Open the pump valve and the strainer valve.
6. Water remains in the strainer still after the cylinder unit was drained.
Drain the strainer by removing the strainer cover.
Draining the hydrobox
WARNING: DRAINED WATER MAY BE VERY HOT
1. Before attempting to drain the hydrobox isolate from the electrical supply to prevent booster heater burning out.
2. Isolate hydrobox from primary water circuit and drain water from hydrobox. Use a suitable heat resistant hose to assist in these operations.
3. Drain any remaining water from booster heater using fitted drain cock and hose, and the drain valve on the primary circuit to safely drain the unit.
4. After the hydrobox is drained, water remains in the following component parts. Drain water completely by checking the inside of the parts.
• Strainer (Remove the strainer cover.)
• Pressure relief valve (Operate the valve.)
OCH729
Recommended tightening torque
[Nm]
42 ± 2
0.25 ± 0.05
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